+1 The combination of Zwift paired with my Kickr for power data in Workout mode (rather than my Quarq) so I can use ERG mode to control resistance is not resulting in reliable and consistent interval efforts.
I did a 2 x 20 min 215w tempo interval workout on Zwift today using that setup & ERG. The Zwift/Kickr combination said the two intervals averaged 214w & 210w, respectively; my Quarq paired with my Garmin 1000 recorded the intervals as 210 & 235, respectively!
That is great agreement on the first interval and both my perceived exertion and HR were consistent with a 210-215w effort. But the Kickr power data clearly went out of whack on the 2nd interval. There was a 25w (10%) difference compared to my Quarq and both perceived exertion and HR were consistent with the 235-240w effort recorded by the Quarq.
Whether it be temperature drift or something else, it’s clear the Kickr was an unreliable source of power output from one interval to the next.
Please allow the use of ERG mode while using an external power meter for power data in workout mode. At least in this case, it’s more than just having consistency with outdoor efforts; it’s a consistency issue between longer intervals during a single workout.